298 



rusted to fully as great an extent as that on either side of it, 

 yet the yield was about 100 per cent, better than on that to 

 which no phosphate was applied, 



" 4. New grounds are, in this section and in our experi- 

 ence, seldom, if ever, troubled with rust, especially if the 

 ground is comparatively high and dry, 



" 5, Our experience and observation tends to confirm us in 

 the opinion that as long as land is abundantly supplied with 

 humus as in old fence rows, near barns, new ground, etc., in 

 short, wherever the land from the presence of this same hu- 

 mus is loose, open, mellow and porous, such land will never 

 suffer to any great extent from rust. On the contrary, when- 

 ever and wherever this humus is deficient and the land packs 

 and bakes after every rain, the roots being thus deprived of 

 air, the plant begins to suffer, the root first and finally the 

 foliage," 



From J. A. Peterkin, Fort Motte, S. C, : 



« I have every foot of my land in oats that is subject to 

 the so-called rust. There are several kinds of land that are 

 subject to this trouble; viz.: a hill slope where the sand has 

 collected near or adjoining a bottom. This will make healthy 

 cotton if the weather is dry from the time the bolls form till 

 it matures, but in wet seasons the soil does not dry out and 

 air cannot enter except through the foliage, which becomes 

 diseased, and then follows the death of the plant ; the deep 

 growing roots are first destroyed. Another class of land that 

 will rust is a black or gray bottom with pipe-clay subsoil. A 

 thin, hard crust forms on the surface, water is retained near 

 the surface by the clay. Any character of rock that forms a 

 pan like the clay causes the same effect, I have a neighbor 

 who has succeeded in making good cotton on bottom land with 

 this pipe-clay subsoil. He has it first thoroughly open drained, 

 then tile drained every twenty feet. He uses stable manure, 

 acid phosphate and kainit. I consider thorough drainage and 

 fertilizers a remedy for the rust." 



A careful reading of the above letters seems to justify 

 the following conclusions : 



1. This disease is largely confined to the older cotton 

 growing States, and it prevails over considerable portions of 

 North and South Carolina, Georgia, Alabama and Mississippi. 



2. It is usually worse on old, worn, sandy lands, but it 

 may appear on any kind of soil when the humus is greatly 

 exhausted. Ta all such cases the building up of Lhe general 



